Component and a method of cooling a component

ABSTRACT

A component and method of cooling a component are provided. The component includes a leading edge, a trailing edge, at least one cavity between the leading edge and the trailing edge, at least one diffusion member adjacent to the cavity. The diffusion member includes an inlet adjacent to the cavity, a metering zone adjacent to the inlet, a diffusion zone adjacent to the metering zone, and an outlet adjacent the diffusion zone and adjacent the trailing edge. The diffusion member provides up to about 70% reduction in flow and uniform cooling of the trailing edge of the component.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/666,813 filed on Jun. 30, 2012 and entitled “ACOMPONENT AND A METHOD OF COOLING A COMPONENT,” the disclosure of whichis incorporated by reference as if fully rewritten herein.

FIELD OF THE INVENTION

The present invention relates generally to turbines. More specifically,to a component and a method of cooling a component in turbine.

BACKGROUND OF THE INVENTION

The objective of designing and building more efficient turbine enginesis a significant one, particularly considering the growing scarcity andincreasing cost of fossil fuels. While several strategies for increasingthe efficiency of turbine engines are known, it remains a challenginggoal because the known alternatives, which, for example, includeincreasing the size of the engine, increasing the temperatures throughthe hot-gas path, and increasing the rotational velocities of the rotorblades, generally place additional strain on parts, including additionalstrain on turbine airfoils, which are already highly stressed. As aresult, improved apparatus, methods and/or systems that reduceoperational stresses placed on turbine airfoils or allow the turbineairfoils to better withstand these stresses are in great demand.

One strategy for alleviating thermal stresses is through cooling theairfoils such that the temperatures experienced by the airfoils arelower than that of the hot-gas path. Effective cooling may, for example,allow the airfoils to withstand higher firing temperatures, withstandgreater mechanical stresses at high operating temperatures, and/orextend the part-life of the airfoil, all of which may allow the turbineengine to be more cost-effective and efficient. One way to cool airfoilsduring operation is through the use of internal cooling passageways orcircuits. Generally, this involves passing a relatively cool supply ofcompressed air, which may be supplied by the compressor of the turbineengine, through internal cooling circuits within the airfoils. As thecompressed air passes through the airfoil, it convectively cools theairfoil, which may allow the part to withstand firing temperatures thatit otherwise could not.

In some instances, the supply of compressed air is released throughsmall holes on the surface of the airfoils. Released in this manner, thesupply of air forms a thin layer or film of relatively cool air at thesurface of the airfoil, which both cools and insulates the part from thehigher temperatures that surround it. This type of cooling, which iscommonly referred to as “film cooling,” however, comes at an expense.The release of the compressed air in this manner over the surface of theairfoil, lowers the aero-efficiency of the engine. As a result, there isan ongoing need for improved cooling strategies for turbine airfoils.

Therefore, a component and a method of cooling a component in turbinethat do not suffer from the above drawbacks is desirable in the art.

SUMMARY OF THE INVENTION

According to an exemplary embodiment of the present disclosure, acomponent is provided. The component may include a leading edge, atrailing edge, at least one cavity between the leading edge and thetrailing edge and at least one diffusion member adjacent to the cavity.The diffusion member may include an inlet adjacent to the cavity, ametering zone adjacent to the inlet, a diffusion zone adjacent to themetering zone, and an outlet adjacent the diffusion zone and adjacentthe trailing edge. The diffusion member may provide up to about 70%reduction in flow and uniform cooling of the trailing edge of thecomponent.

According to another exemplary embodiment of the present disclosure, amethod of cooling a component is provided. The method may includeproviding the component. The component may include a leading edge, atrailing edge, at least one cavity between the leading edge and thetrailing edge and at least one diffusion member adjacent to the cavity.The diffusion member may include an inlet adjacent to the cavity, ametering zone adjacent to the inlet, a diffusion zone adjacent to themetering zone, and an outlet adjacent the diffusion zone and adjacentthe trailing edge. The diffusion member may provide up to about 70%reduction in flow and uniform cooling of the trailing edge of thecomponent. The method may include circulating cooling air in the atleast one cavity through the diffusion member. The heat from thecomponent may be removed through the diffusion zone.

Other features and advantages of the present invention will be apparentfrom the following more detailed description of the preferredembodiment, taken in conjunction with the accompanying drawings whichillustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective schematic of a component of the presentdisclosure.

FIG. 2 is a blown-up view of FIG. 1 of the diffusion zone of the presentdisclosure.

FIG. 3 section view of FIG. 1 taken along line 3-3 of the presentdisclosure.

FIG. 4 is a blown-up view of the diffusion zone of FIG. 3 of the presentdisclosure.

FIG. 5 is an alternative embodiment of the diffusion zone of FIG. 3 ofthe present disclosure.

FIG. 6 is an alternative embodiment of the diffusion zone of the presentdisclosure.

Wherever possible, the same reference numbers will be used throughoutthe drawings to represent the same parts.

DETAILED DESCRIPTION OF THE INVENTION

Provided is a component and a method of cooling a component.

One advantage of an embodiment of the present disclosure includesreducing parasitic flows from a turbine. Another advantage of anembodiment of the present disclosure includes reducing the dischargevelocity of the nozzle trailing edge cooling slots. Yet anotheradvantage of the present disclosure is increased engine efficiency.

According to one embodiment, a component including a leading edge, atrailing edge, at least one cavity between the leading edge and thetrailing edge, and at least one diffusion member adjacent to the cavityis provided. Component may generally be a hot gas flow path componentand may include turbine components, such as, but not limited to,nozzles, blades and shrouds. According to one embodiment the diffusionmember may provide up to about 70% reduction in flow and uniform coolingof the trailing edge of the component. In one embodiment, the componentmay be a ceramic matrix composite. In another embodiment, the componentmay be a superalloy metal, such as but not limited to nickel-basedsuperalloy, cobalt-based superalloy, or a combination thereof.

For example, FIG. 1 is a perspective schematic of a component 100. Forexample, as depicted, component 100 may be a nozzle. Component 100 mayinclude an airfoil 102. Airfoil 102 may be a member between the innerand outer turbine flow path with purpose to change the flow gas pathdirection. Airfoil may include a leading edge 110, a trailing edge 112,and a body 104 between leading edge 110 and trailing edge 112. As shownin FIG. 2, for example, component 100 may include at least one cavity200, 310, 320 between leading edge 110 and trailing edge 112. Component100 may include at least one diffusion member 130 adjacent to the atleast one cavity.

According to one embodiment, diffusion member may include an inletadjacent to the cavity, a metering zone adjacent to the inlet, adiffusion zone adjacent to the metering zone, and an outlet adjacent thediffusion zone and adjacent the trailing edge. For example, as shown inFIG. 2, diffusion member 130 may include an inlet 210 adjacent to cavity200. Diffusion member 130 may include a metering zone 220 adjacent toinlet 210. Diffusion member 130 may include a diffusion zone 230adjacent to metering zone 220. Diffusion member 130 may include anoutlet 240 adjacent diffusion zone 220 and adjacent trailing edge 112.Diffusion member 130 may provide up to about 70% reduction in flow anduniform cooling of trailing edge 112 of component 100. Velocity of flowat outlet 240 may be significantly reduced. Diffusion member 130 mayexpand the cross section area from inlet 210 to outlet 240. As usedherein “flow expansion” may be a process in which the mass flux isreduced with increasing through-flow area, or a device that enables saidprocess, such as the diffusion member 120. As used herein “flowmetering” may be a process or device that controls the quantity of flowtraversing the member containing the metering process or device.

As shown in FIG. 2, inlet 210 may be the location that flow enterstrailing edge 112 cooling scheme from aft cavity 200 (see FIG. 3). Inlet210 may be typically short in length with the ratio of the length tohydraulic diameter being less than about 5. Inlet 210 may have uniquegeometric characteristics intended to reduce its meteringcharacteristics. Metering zone 220 may be primarily a controlledgeometry feature the size of which has the most significant impact onthe flow rate passing through trailing edge 112 cooling scheme. Meteringzone 220 may have a secondary geometry feature that causes or isintended to cause a reduction in the flow rate. Secondary metering mayhave a non-negligible impact on flow rate but may not be the flowcontrolling feature.

Diffusion zone 230 or expansion region may be a region with through-flowarea increase of about 150% to about 500%, between the metering zone 220and outlet 240. Diffusion zone 230 may include a diffusion angle 232.Diffusion angle 232 may be any angle that provides the desired expansionof flow. Outlet 240 may be the location where flow exits internalportion of trailing edge 112 cooling scheme. Outlet 240 may becharacterized by film coverage and in the event outlet 240 bisects thetrailing edge 112 with no film coverage zone, then outlet 240 may havean open-to-solid ratio in the range of about 25% to about 100%. As usedherein, “film coverage,” may be measured in the direction orthogonal tothe flow, and is the fraction of the distance that is exposed to outlet240.

FIG. 3 is a sectional view along line 3-3 of FIG. 1 and shows forwardcavity 320 adjacent leading edge 110. Second cavity 310 may be adjacentforward cavity 320. Aft cavity 200 may be adjacent diffusion member 130.Diffusion member 130 may be adjacent external portion 350. Externalportion 350 may be the distance between outlet 240 of diffusion member130 and airfoil closeout, having a ratio of length (L) to hydraulicdiameter (D) in the range of about zero to about twelve. In oneembodiment, when the L/D ratio may be finite, the film coverage may bein the range of about 33% to 100%. In another embodiment when the L/Dratio may be zero, the outlet 240 may have “open” coverage in the rangeof about 33% to 100%.

According to one embodiment, a diffusion member is provided. Forexample, FIG. 4 illustrates a schematic blow-up of FIG. 3 highlightingthe diffusion member 130. Inlet 210 may be adjacent to aft cavity 200.Metering zone 220 may be adjacent inlet 210. Diffusion zone 230 may beadjacent metering zone 220. Outlet 240 may be adjacent diffusion zoneand external portion 350 of airfoil 102 trailing edge 112. In analternative embodiment, as shown in FIG. 5, outlet 240 may exit at baseof trailing edge 112, having no breakout length.

According to one embodiment, a diffusion member may include two or morediffusion zones. For example, as illustrated in FIG. 6 diffusion member130 may include inlet 210 adjacent to aft cavity 220 of component 100.Inlet 210 may be adjacent to metering zone 220. There may be two or morediffusion zones 230 adjacent to metering zone 220. Each diffusion zone230 may provide the desired expansion and decrease in flow. Eachdiffusion zone 230 may include an outlet 240 adjacent to trailing edge112.

Diffusion member 130 may be formed in component 100 using any suitabletechnologies, such as, but not limited to, lasers, or electricaldischarge machining (EDM).

While the invention has been described with reference to a preferredembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims.

What is claimed is:
 1. A component comprising: a leading edge; atrailing edge; at least one cavity between the leading edge and thetrailing edge; at least one diffusion member adjacent to the cavity, thediffusion member including: an inlet adjacent to the cavity; a meteringzone adjacent to the inlet; a diffusion zone adjacent to the meteringzone; and an outlet adjacent the diffusion zone and adjacent thetrailing edge; wherein the diffusion member provides up to about 70%reduction in flow and uniform cooling of the trailing edge of thecomponent.
 2. The component of claim 1, wherein the component is aceramic matrix composite.
 3. The component of claim 1, wherein thecomponent is a superalloy metal.
 4. The component of claim 1, whereinthe component is a blade, a nozzle, or a shroud.
 5. The component ofclaim 1, wherein the diffusion member expands the cross section areafrom the inlet to the outlet.
 6. The component of claim 1, wherein thediffusion zone increases through-flow area from about 150% to about 500%between the metering zone and the outlet.
 7. The component of claim 1,wherein the outlet has an open-to-solid ratio of about 25% to about100%.
 8. A method of cooling a component comprising: providing thecomponent having: a leading edge; a trailing edge; at least one cavitybetween the leading edge and the trailing edge; at least one diffusionmember adjacent to the at least one cavity, the diffusion memberincluding: an inlet adjacent to the cavity; a metering zone adjacent tothe inlet; a diffusion zone adjacent to the metering zone; and an outletadjacent the diffusion zone and adjacent the trailing edge; wherein thediffusion member provides up to about 70% reduction in flow and uniformcooling of the trailing edge of the component; and circulating coolingair in the at least one cavity through the diffusion member, whereinheat from the component is removed through the diffusion zone.
 9. Themethod of claim 8, wherein the component is a ceramic matrix composite.10. The method of claim 8, wherein the component is a superalloy metal.11. The method of claim 8, wherein the component is a blade, a nozzle,or a shroud.
 12. The method of claim 8, wherein the diffusion memberexpands the cross section area from the inlet to the outlet.
 13. Themethod of claim 8, wherein the diffusion zone increases through-flowarea from about 150% to about 500% between the metering zone and theoutlet.
 14. The method of claim 8, wherein the outlet has anopen-to-solid ratio of about 25% to about 100%.